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Re: [PATCH][AArch64] Improve aarch64_case_values_threshold setting
- From: Wilco Dijkstra <Wilco dot Dijkstra at arm dot com>
- To: Evandro Menezes <e dot menezes at samsung dot com>, "gcc-patches at gcc dot gnu dot org" <gcc-patches at gcc dot gnu dot org>
- Cc: nd <nd at arm dot com>
- Date: Mon, 25 Apr 2016 19:21:15 +0000
- Subject: Re: [PATCH][AArch64] Improve aarch64_case_values_threshold setting
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Evandro Menezes wrote:
> I assume that you mean that such improvements are true for
> -mcpu=generic, yes? On which target, A53 or A57 or other?
It's true for any CPU setting. The SPEC results are for Cortex-A57
however I wrote a microbenchmark that shows improvements on
all targets I have access to. The GCC switch expansion is awful, so
even with a good indirect predictor it is better to use conditional
branches.
Wilco